Recently, vehicles are equipped with devices that provide information of various types to a plurality of subscribers in real-time via a wired or wireless communication network. For example, a remote control system can remotely communicate with devices equipped in the vehicle such as a telematics terminal. As telematics services have increased, reliability of additional functions, such as remote control systems, has a great influence on the degree of customer satisfaction.
The remote control system can be provided by a server located remote of the vehicle as well as a telematics unit or a portable terminal (e.g., a remote control terminal or a smart phone), which is engaged with the vehicle. The server can be coupled with the telematics unit or the portable terminal via wireless communication. The remote control system, requested by the driver through mutual wireless communication between the vehicle and the portable terminal, can provide useful information of the vehicle, such as a diagnostic status, vehicle ignition lock, vehicle speed deceleration, remote air conditioning control, remote door lock control, theft detection, and so on.
In addition, the remote control system can remotely control the vehicle based on a short message service (SMS) in response to a driver's request after the driver completes an authentication process by, for example, calling a telematics center operating the server. For example, when a user uses a mobile device to request a remote control service to a server in a telematics center, the server in the telematics center communicates with a telematics unit in the vehicle for delivering a corresponding service command. When the telematics center receives a response from the telematics unit, the server in the telematics center then delivers a message such as a SMS message corresponding to the response (e.g., “successfully completed”) to the mobile device to achieve or complete the remote control service.
Even after the telematics unit enters a sleep mode, the telematics unit can receive a text message or a voice call through discontinuous reception (DRX) for paging from a mobile communication center such as a Core Network (CN) or UMTS Terrestrial Radio Access Network (UTRAN) which communicates with the server.
The telematics terminal needs a booting time to be available to the user if power is supplied after an ignition is turned on. However, a user or driver is inconvenienced when the booting time increases. In the worst case, the user or driver could not use the telematics terminal at the desired time. Considering these characteristics, the telematics terminal may be operated through power stored in an in-vehicle battery.
Further, in a sleep mode, a communication modem is configured to perform wireless communication with a base station to support the requested remote service, such as remote start, even while the ignition is turned off. However, in order to prevent discharge of the battery because the communication modem uses power stored in the battery in the sleep mode, the vehicle could turn off the communication modem completely for a predetermined standby time after the ignition is turned off.
In a state where the power of the communication modem is completely blocked and the user is unable to connect to the vehicle or use a telematics service performed through the mobile phone or the call center. In this case, if a service is not properly provided, the user may not understand the reason of service error (e.g., a service failure error from the call center or a discharge of the in-vehicle battery).
Meanwhile, power saving algorithms are needed due to the recent increase of broadband LTE data modems in vehicles, as well as the complexity of power consumption caused by communication using different communication protocols a mixed communication networks of 2G/3G/4G. Conventionally, dark current consumption in the communication modem may be calculated while the ignition is turned off based on a single communication mode. Thus, when the communication modes such as 2G/3G/4G can be used selectively and interchanged with each other, it may not be possible to accurately determine whether a dark current supplied to the devices operating using the power of the battery exceeds a predetermined level.
Accordingly, the TMU network is relatively considering packet transmission/reception between a base station and a TMU terminal of a vehicle, rather than an algorithm filled with a simple calculation formula. Further, in response to a communication mode at a handover region (“handover” is a solution for changing a cell when a mobile terminal moves from a based station area to another base station area), an accurate current consumption calculation is required to accurately calculate current consumption based on a shadow communication region (areas where radio waves from the base station cannot be received or mixed with shaded areas), a superposition area of strong and weak electric fields (the intensity of the received electric field at the time of the remote service is the region where the strong electric field and the weak electric field are overlapped), and international roaming